The Umarex HK45 by KWA has taken the designs of KWAs successful USP series and has incorporated them into the Umarex HK45. Much like its real firearm counterpart, special attention was given to the pistols overall ergonomics and controls. The new grip works in conjunction with the included interchangeable backstraps. This feature enable the user to swap between grip sizes for maximum comfort. While the ambidextrous slide release and an enlarged magazine lever accommodate both left handed or right handed operators. A full 20mm picatinny rail built on the lower frame allows for a wide variety of weapon attachments without the need for adapters. The updated features of the HK45 are further enhanced by KWAs new designed Hop Up system which increases the performance capabilities of this modern combat pistol.